1. Field of the Invention
The present invention relates to a technique for controlling writing and reading of data from a upper device in a storage control device equipped with a plurality of disk drives.
2. Description of the Related Art
There are hitherto the transaction and database as principal applications of the storage control device such as a disk array system. In such applications severe requirements are thus imposed as regards high performance and high reliability. Therefore, the storage control device used for this application is equipped with a hard disk drive (HDD) with high performance and high reliability. As the HDD fully complying with the imposed requirements must be highly reliable as one of parts, it would be usually highly expensive.
A technique for saving dissipation power of the disk array system equipped with such HDD's has been proposed.
Such a technique is disclosed in, for example, JP-A-2000-293314.
However, such a technique of the prior art is not effective for the disk array system or storage control device used for the applications such as back-up, restore, archive and the like.